This invention relates generally to suspension mechanism for supporting a device, such as a magnetic head, capable of reading and or writing data to or from a data storage medium. More particularly, the invention relates to an improved gimbal suspension for reducing vibration experienced by a disk head slider.
Data storage devices employing one or more rotating disks with one or more surfaces on each disk useable for storing digital data are well known. Such data storage devices are often referred to as disk drives. Disk drives provide a relatively low cost means for randomly storing and accessing data. Typically, each data storage surface is divided into a number of concentric circular data tracks. Each data track is typically further divided into a number of data track locations or sectors capable of storing information. Generally, data is written or accessed by positioning a read/write magnetic head held by a head suspension for supporting the head over a selected data track while the disk is rotating. The read/write head can then read or write data to or from track sectors located on that data track. The read/write head is typically biased against the surface of the disk such that, as the disk rotates, the read/write head xe2x80x9cfliesxe2x80x9d on an air bearing above the disk.
A typical suspension system in a hard disk drive includes a voice coil motor configured for rotating an actuator arm over a desired location on the disk by rotating the actuator arm around an axis on a support spindle. A head suspension or load beam is coupled to the end of the actuator arm, and frequently, a flexure that carries the read/write head is coupled to the end of the load beam. This type of suspension may be used in both magnetic and non-magnetic data storage devices.
As efforts to increase track density continue, the radial spacing between concentric data tracks on the disks decreases. As the track density increases, it is increasingly difficult for known motor servo systems to quickly and precisely position the read/write head over a desired data track. This problem is complicated by the increased susceptibility of such drives to sources of read/write errors. For example, errors can arise from mechanical vibration of the read/write head. Undesirable levels of vibration may cause read/write errors, and may also delay the transfer of data because the data cannot be confidently transferred until the amplitude of vibration has substantially decayed.
What is needed is an improved gimbal suspension mechanism for supporting a head capable of reading and or writing data to or from a data storage medium that reduces undesirable vibration of the head, thereby potentially reducing wear loss of the disk and head, and potentially decreasing seek times.
Accordingly, the current invention is a head suspension assembly comprising a vibration dampening coupling between a protrusion on a support, and a support plate to which a slider is preferably rigidly coupled. In a preferred embodiment, the slider support plate is coupled to and supported by a flexure configured to allow the slider support plate to gimbal within desired parameters. The flexure is configured and positioned so that the slider support plate coupled to the flexure tends to exert pressure against the protrusion on the support structure. The vibration damping coupling between the protrusion on the support structure and the slider support plate preferably comprises a vibration dampening material selected for a low static modulus, which reduces mechanical vibration by absorbing kinetic energy and releasing the energy as heat. The gimbaling function of the suspension is not significantly effected by the damping material because the damping effect tends to be significant primarily when there is an undesirable relative velocity or movement with respect to time between the protrusion on the support structure and the slider support plate. The support structure is preferably a load beam, or a structure coupled to a load beam. The load beam preferably has a top surface, and a bottom surface, and a distal end with the protrusion extending from a top surface or a bottom surface of the load beam. The protrusion on the top surface or on the bottom surface of the load beam is preferably defined by a corresponding depression on the opposite surface of the load beam. The vibration dampening material is preferably a visco-elastic material, more preferably formed into a sheet of any desired shape.